Using Windows Server 2016 to host a more stable Go Http server for UI tests

Validation: tryjob

Bug: 1105203
Change-Id: Ife6434732a999e32a44868bcf7bb996a72e907f7
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/2533308Reviewed-by: Owen Min <zmin@chromium.org>
Commit-Queue: Xiang Ji <jxiang@google.com>
Cr-Commit-Position: refs/heads/master@{#827057}

chrome/test/enterprise/e2e/infra/chrome_ent_test_case.py

@@ -40,7 +40,7 @@ class ChromeEnterpriseTestCase(EnterpriseTestCase):
       'dc': 'win2019-dc',
   }
   # Current Win Server version for testing
-  win_config = win_2019_config
+  win_config = win_2016_config
 
   def InstallChrome(self, instance_name):
     """Installs chrome.

chrome/test/enterprise/e2e/policy/policy_test.asset.textpb

@@ -10,20 +10,20 @@ ad_domain {
   netbios_name: 'example'
 
   domain_controller {
-    windows_machine: 'win2019-dc'
+    windows_machine: 'win2016-dc'
   }
 }
 
 # the domain controller.
 windows_machine {
-  name: 'win2019-dc'
-  machine_type: 'win2019'
+  name: 'win2016-dc'
+  machine_type: 'win2016'
   network_interface { network: 'primary' }
 }
 
 windows_machine {
-  name: 'client2019'
-  machine_type: 'win2019'
+  name: 'client2016'
+  machine_type: 'win2016'
   network_interface { network: 'primary' }
   container { ad_domain: 'test1.com' }
 }
\ No newline at end of file